1. Field of the Invention
The present invention relates to an immune-boosting food composition containing a green tea hydrolysate as an active component and a method for preparing the same.
2. Description of the Related Art
Green tea from leaves of Camellia sinensis L. is the most widely consumed tea throughout the world, which contains a variety of nutrients such as polyphenols, polysaccharides and vitamins and is known to be effective in reducing the risk of a variety of diseases. For example, polyphenol present in green tea is receiving considerable attention as a main active component of green tea. In particular, epigallocatechin gallate (EGCG) is known to exhibit a variety of biological activities such as antioxidant and antiarteriosclerotic activities. For this reason, research associated with green tea is mostly focused on EGCG of young leaves which is suitable for preparation of green tea.
However, it is not considered that EGCG is the sole component in charge of the pharmaceutical activities found in green tea and the possibility of presence of other substances having biological activities such as polysaccharides in mature leaves of green tea still remains. Meanwhile, pectin is a polysaccharide mainly present in primary cell walls and middle lamella of high plants, which is a promising material which will exhibit superior action as a source of dietary fiber and physiological effects. Pectin was known as a polymer (α-D-1,4-polygalacturonic acid) in which a plurality of molecules of D-galacturonic acid (GalA) are bonded to one another at an α-1,4 linkage. However, since the detailed structure of pectin was recently found through structural analysis technologies, it has been reported that pectin is mainly composed of homogalacturonan (HG), but has a structure in which homogalacturonans (HG) are covalently bonded to rhamnogalacturonans (RG) in which oligosaccharides and polysaccharides are branch-bonded (FIG. 1).
The inventors of the present invention discovered that fractions obtained by hydrolyzing young and mature leaves of green tea commonly used for drinking with a specific enzyme exhibit immune boosting and anticancer effects. The present invention has been completed based on this discovery.